Method and apparatus for submersible or self contained aeration of liquid medium

ABSTRACT

An apparatus and method for mixing gas and liquid comprising a submersible or a self contained, self powered floating pressurized dome aeration apparatus housing multi-shaft intermeshed plurality of mixing discs with a remote umbilical power and control unit and process for adding dissolved gas (oxygen) into fluid (water), wherein intermeshed rotating sets of discs operate on parallel shafts driven by variable speed motors or drives, and strakes are radially mounted on the discs to carry liquid up into a mixing area and to carry air and liquid down into a mixing area resulting in a shear force that drives air into the oxygen depleted liquid.

CROSS-REFERENCE AND PRIORITY CLAIM TO RELATED APPLICATIONS

To the fullest extent permitted by law, the present United StatesNon-Provisional patent application is a continuation-in-part of, andhereby claims priority to and the full benefit of U.S. Non-Provisionalpatent application entitled, “Method and Apparatus for Aeration ofLiquid Medium in a Pipe,” filed on May 12, 2009, having assigned Ser.No. 12/464,852 (a continuation-in-part of application Ser. No.12/187,905, filed on Aug. 7, 2008), which claims priority to and thefull benefit of U.S. Non-Provisional patent application entitled “Methodand Apparatus for Aeration of Liquid Medium,” filed on Aug. 7, 2008,having assigned Ser. No. 12/187,905 (a divisional of application Ser.No. 11/131,113, filed on May 17, 2005), which claims priority to and thefull benefit of U.S. Non-Provisional patent application entitled “Methodand Apparatus for Aeration of Liquid Medium,” filed on May 17, 2005,having assigned Ser. No. 11/131,113, and issued under U.S. Pat. No.7,427,058 on Sep. 23, 2008, incorporated herein by reference in theirentirety.

TECHNICAL FIELD

This disclosure relates to an apparatus and method for mixing gas, suchas air, with liquid, and more specifically the disclosure relates toaeration of wastewater, sewage and industrial waste including any bodyof water or liquid.

BACKGROUND

Wastewater from both municipal sewage systems and from industrial wasteproduct exhausting systems is usually collected in large ponds, ditches,or basins that are referred to as wastewater ponds. Such ponds may be afew to several feet deep and may cover quite a number of acres ofsurface area. The wastewater usually includes large amounts of organicand inorganic waste material that, if left untreated, creates severeodors and can generates toxic products.

Moreover, EPA has published dissolved oxygen (DO) criteria for liquid,such as fresh, salt and brackish water, and wastewater, sewage andindustrial wastewater discharges into the same bodies of water toprotect organisms and their uses from the adverse effects of low DOconditions. The Agency developed these criteria because hypoxia (lowdissolved oxygen) is a significant problem for lakes, streams, rivers,and coastal waters that receive a lot of runoff that contain nutrients(for example, nitrogen and phosphorous and other oxygen-demandingbiological wastes). Excessive nutrients in aquatic systems stimulatealgae growth, which in turn uses up the oxygen needed to maintainhealthy fish, shellfish, and other aquatic life populations.

EPA's Environmental Monitoring and Assessment Program (EMAP) for lakes,streams, rivers, and coastal waters has shown areas exposed to somedissolved oxygen concentrations of less than 5 mg/L. Long periods of DObelow 5 mg/L can harm larva life stages for many fish, shellfish, andother aquatic life populations.

The EPA's dissolved oxygen criteria apply to both continuous and cycliclow DO conditions. If the DO conditions are always above the chroniccriterion for growth (4.8 mg/L), the aquatic life at that locationshould not be harmed. If the DO conditions at a site are below thejuvenile/adult survival criterion (2.3 mg/L), there is not enough DO toprotect aquatic life.

Under the Clean Water Act (CWA), states, territories, and tribes mustadopt water quality criteria to protect designated uses. The EPA haspromulgated regulations to implement this requirement including levelsof DO (see 40 CFR 131).

The most common method of wastewater treatment uses an activated sludgeprocess. This process involves three major steps. The primary treatmentstage consists of a simple separation between dense sludge, which issent to an incinerator or land fill, and the remaining effluent liquidsludge then undergoes secondary treatment. Secondary treatment is wherethe biochemical consumption of organic material takes place. Themicroorganisms present in the liquid sludge feast on the biomass in thewastewater pond. Extensive aeration is needed for the bacteria toconsume the organic wastes.

The third phase of treatment can be simple or extensive depending uponthe extent of pollution and the requirements for water purity. Itspurpose is to remove inorganic pollutants as well as any organic massnot removed by the primary and secondary stages. Lastly, the treatedwater is discharged back into the environment. This discharge must meetfederal, state, county and city government standards for dischargedwater, such as minimum dissolved oxygen levels deemed necessary toaccommodate marine life, before such wastewater can be discharged into ariver or stream.

The activated sludge process is a biochemical process in which aerobicbacteria consume the organic pollutants in wastewater. Because thebacteria are aerobic, their efficiency of consumption is very dependentupon the amount of available oxygen dissolved in the liquid sludge. Inthe wastewater treatment process, aeration introduces air into a liquid,providing an aerobic environment for microbial degradation of organicmatter. The purpose of aeration is two-fold: to supply the requiredoxygen to the metabolizing microorganisms and to provide mixing so thatthe microorganisms come into intimate contact with the dissolved andsuspended organic matter.

Various aeration approaches have been used; the two most common aerationsystems are subsurface and mechanical. In subsurface aeration systems,air or oxygen is pumped below the surface to a diffuser or other devicesubmerged in the wastewater. Fine pore diffusion is a subsurface form ofaeration in which air is introduced in the form of very small bubblesinto the wastewater pond. One type of an oxygen diffuser for wastewatertreatment process requires constant movement of the diffuser todifferent levels and positions within the wastewater pond and performsminimal mixing of the wastewater and oxygen. In addition, un-reacted airor oxygen bubbles make their way to the surface and do not becomedissolved in the liquid. If oxygen is the source, then the oxygen thatmakes it to the surface of the wastewater pond is wasted as it vents tothe air above the pond.

Mechanical aeration and mixing systems take on various forms, such asdowndraft pumps, which force surface water to the bottom, updraft pumps,which produce a small fountain, and paddle wheels, which increase thesurface area of the water. In addition, all such devices mix wastewaterby moving large amounts of heavy water or hurling it into the airresulting in high energy consumption for these devices. Some suchdevices generate large amounts of odor and foam while agitating thewastewater and consume large amounts of electrical power resulting inhigh electricity cost for operation.

Therefore, it is readily apparent that there is a need for an economicalapparatus and method for aeration of wastewater, sewage and industrialwaste, or other liquids, such as fresh, salt and brackish water, andmore particularly, a process for efficiently adding dissolved oxygeninto such liquids while minimizing odor, foam and energy consumption.

BRIEF SUMMARY

Briefly described, in an example embodiment, the present disclosureovercomes the above-mentioned disadvantages and meets the recognizedneed for such a device by providing a method and apparatus for mixinggas, such as air, with liquid, such as fresh, salt and brackish water,wastewater, sewage and industrial waste.

According to its major aspects and broadly stated, the presentdisclosure in its example form is a floating pressurized dome aeratordevice and process for adding dissolved oxygen into liquid, such asfresh, salt and brackish water, wastewater, sewage and industrialwastewater.

More specifically, the aerator device has two or more partiallysubmerged interleaved sets of discs operating in rotational unison alongparallel shafts driven by variable speed drives. One or more strakeswith end caps are mounted on the discs in radial fashion, extending fromthe hub to the edge of the disc. The strakes on one disc bring theliquid up to the liquid line and the strakes on the other disc bring theair down to the liquid line and in close contact with each other in amixing area just below the liquid line. This force mixes the oxygen fromthe air into the oxygen-depleted liquid, thus increasing the dissolvedoxygen content of the liquid, such as fresh, salt and brackish water,wastewater, sewage and industrial waste.

Still more specifically, an example embodiment of an apparatus andmethod for mixing gas and liquid comprising a pipe having an enclosurepositioned in-line with said pipe, wherein a sealed space is defined, atleast one blower, said blower regulates the barometric pressure in saidsealed space, wherein intermeshed rotating sets of discs operate onparallel shafts driven by variable speed drives, and strakes areradially mounted on the discs to carry liquid up into a mixing area andto carry air and liquid down into a mixing area resulting in a shearforce that drives air into the oxygen depleted liquid. In the sealedspace the barometric pressure is raised by a blower, in order to popfoam bubbles and allow for optimum mixing of air into the oxygendepleted liquid and to regulate the liquid line within the sealed space,thereby preventing the escape of foam, noise and odorous gases into thelocal environment.

Another example embodiment of an apparatus and method for mixing gas andliquid comprising a submersible pressurized dome aeration apparatushousing multi-shaft intermeshed plurality of mixing discs with a remoteumbilical power and control unit and process for adding dissolved gas(oxygen) into fluid (water).

Another example embodiment of an apparatus and method for mixing gas andliquid comprising a self contained floating pressurized dome aerationapparatus housing multi-shaft intermeshed plurality of mixing discs andprocess for adding dissolved gas (oxygen) into fluid (water).

Accordingly, a feature of the apparatus and method for mixing gas andliquid is its ability to create a shear force between the liquid on theleading edge of opposing strakes within the mixing area to efficientlymix the gas and the liquid.

In addition, the strakes have bleed holes on their trailing face. Theend caps force liquid fluid eddy currents on the liquid side andflurries of bubbles of air on the gas side through the bleed holes ofthe trailing edge of the strake into the mixing area to efficiently mixthe air and liquid, such as fresh, salt and brackish water, wastewater,sewage and industrial waste.

Accordingly, a feature of the apparatus and method for mixing gas andliquid is its ability to sustain a larger number of aerobic dependentbacteria than traditional methods resulting in an increased biochemicalconsumption of organic material in the liquid or wastewater pond.

In use, the aerator device is placed on a floating platform to keep theaerator device at a set position relative to the liquid line. Thefloating apparatus is covered with an airtight cover or dome, whereinthe barometric pressure is raised under the cover or dome by an airblower to create an atmosphere under the dome with an increasedbarometric pressure.

Another feature of the apparatus and method for mixing gas and liquid isthat the variable barometric pressure allows for optimum atmosphericdissolution under the cover or dome.

Another feature of the apparatus and method for mixing gas and liquid isthat the foam must travel back beneath the liquid-line of the liquid toescape the floating apparatus resulting in further aeration of theliquid sludge.

Another feature of the apparatus and method for mixing gas and liquid isthat the liquid inlet is beneath the liquid-line creating a sealedenvironment.

Another feature of the apparatus and method for mixing gas and liquid isthat the liquid discharge is beneath the liquid-line creating a sealedenvironment.

Another feature of the apparatus and method for mixing gas and liquid isits ability to minimize foam generated during use, wherein the raisedbarometric pressure in the dome serves the function of popping thebubbles created by the mechanical mixer.

Another feature of the apparatus and method for mixing gas and liquid isthat the cover or dome traps odorous gases preventing their escape intothe local environment, resulting in an odor free operation.

Another feature of the apparatus and method for mixing gas and liquid isthat the cover or dome traps the noises generated by the mechanicalagitation preventing their escape into the local environment andresulting in an essentially noise free operation.

Another feature of the apparatus and method for mixing gas and liquid isthat the strakes may be configured to provide a cutting or choppingaction or edge for operation in high solid and/or high fiber, such ashair and bio solids, prevailing in primary wastewater sludge ponds.

Another feature of the in line pipe apparatus and method for mixing gasand liquid is its ability to utilize energy gathering rotors' operatingpassively with drive system disengaged if pipe current is adequate todrive the apparatus.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to operate at any depth limited only by length ofconnecting umbilical and the availability of supply pressure to overcomewater pressure at operating depth.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to utilize the efficiencies of Henry's Law anddissolves gas at depth under great pressure, where increased oxygen isretained in liquid due to the higher pressure.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to operate continuously in any weather, and is notaffected by surface conditions.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to recover from loss of power and air pressurewithout retrieval by reapplying air pressure; resulting in an air pocketunder the dome of the submerged unit.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to be retrieved from its submerged position byrouting compressed air to ballast tanks and adding buoyancy to the unit.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to hide the remote power and control unit,especially in aesthetically or environmentally sensitive areas such asdeveloped water front or wildlife habitat as well as by adding a soundattenuated housing or positioning the power unit inside a building ormechanical room.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to position the power and control unit on a bargeor other vessel, which may be used as a tender for submerged unit,retrieving, servicing or relocating both power and submerged unit asnecessary.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to utilize energy gathering rotors, provided watermovement relative to the submerged unit is sufficient for passive poweroperation.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to operate at the very bottom of a shippingchannel where the submerged unit is anchored causing no delay to passingship traffic.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to be virtually invisible to public, while beingof vital service to the environment, industry, and commerce.

Another feature of the submerged apparatus and method for mixing gas andliquid is its ability to utilize energy gathering rotors' operatingpassively with drive system disengaged if current is strong or unit isbeing towed.

Still more specifically, an apparatus for treating fluid by exposing thefluid to gas, the apparatus including a dome, a lower housing supportsthe dome, the lower housing connected to the dome, wherein a sealedspace is defined under the dome and above a fluid line within said lowerhousing, an aeration means positioned within the sealed space andpartially submerged below the fluid line, wherein the aeration meanscomprises one or more parallel shafts, at least one first discpositioned axially on one of the shafts, at least one second discpositioned axially on another of the shafts, wherein the second disc isinterleaved relative to the first disc, and wherein a surface of thefirst disc rotates in a direction opposite a surface of the second discrelative to each other resulting in a mixing area therebetween; at leastone air source, said air source enabling an effect therefrom on thebarometric pressure in said sealed space, and wherein said apparatus issubmerged to depths having increased pressure below a waterline.

Another feature of the self contained apparatus and method for mixinggas and liquid is its portability enabling quick re-positioning in anexisting body of water and mobility from one aquatic area to another. Noinfrastructure of any kind needed to operate the apparatus other than afuel supply.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to scale to any size with currenttechnology and materials, whether as a small craft or a large barge.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to operate autonomously utilizingcurrently available technology and utilizing global positioning and thelike.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to have an operator on board to functionin complex patterns like a street sweeper.

Another feature of the self contained apparatus and method for mixinggas and liquid is its setup and retrieval time are reduced to minutesnot hours or days, since it is equipped with fuel and a power supply.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to operate without being tethered, poweror control cables, guides or other devices.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to be instantly deployable or air liftedin a crises situation, such as low dissolved oxygen conditions at a fishfarm, sewage spills, and algae blooms, i.e., anywhere oxygen needs to berestored quickly.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to add a cutter head to the apparatus toeradicate, remove, or harvest algae or other aquatic plant growth.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to utilize energy gathering rotors'operating passively with drive system disengaged if current is strong orunit is being towed.

Another feature of the self contained apparatus and method for mixinggas and liquid is its ability to be tethered and operate as a selfcontained stationary unit.

Still more specifically, an apparatus for treating fluid by exposing thefluid to gas, the apparatus including a dome, a lower housing supportsthe dome, the lower housing connected to the dome, wherein a sealedspace is defined under the dome and above a fluid line within said lowerhousing, an aeration means positioned within the sealed space andpartially submerged below the fluid line, wherein the aeration meanscomprises one or more parallel shafts, at least one first discpositioned axially on one of the shafts, at least one second discpositioned axially on another of the shafts, wherein the second disc isinterleaved relative to the first disc, and wherein a surface of thefirst disc rotates in a direction opposite a surface of the second discrelative to each other resulting in a mixing area therebetween; at leastone air source, said air source enabling an effect therefrom on thebarometric pressure in said sealed space, and wherein a flotation hullfor channeling fluid into the sealed space and for storage fuel therein.

These and other features of the apparatus and method for mixing gas andliquid will become more apparent to one skilled in the art from thefollowing Detailed Description of the Preferred and Selected AlternateEmbodiments and Claims when read in light of the accompanying drawingFigures.

BRIEF DESCRIPTION OF THE DRAWINGS

The present apparatus and method for mixing gas and liquid will bebetter understood by reading the Detailed Description of the Preferredand Selected Alternate Embodiments with reference to the accompanyingdrawing Figures, in which like reference numerals denote similarstructure and refer to like elements throughout, and in which:

FIG. 1 is a cross-sectional illustration of the aeration apparatusaccording to an example embodiment;

FIG. 2 is a front sectional view of the aeration apparatus of FIG. 1;

FIG. 3 is perspective view of a strake with bleed holes according to anexample embodiment;

FIG. 4A is front sectional view of a pair of discs showing theirdirection of rotation according to an example embodiment;

FIG. 4B is a top sectional view of disc array showing two sets of discsinterleaved amongst each other according to an example embodiment;

FIG. 5 is an enlarged partial sectional view depicting the dynamics ofthe liquid gas mixing area, showing radial strakes and bleed holesaccording to an example embodiment;

FIG. 6 is a side view of a standard industrial waste water or dischargepipe;

FIG. 7 is a side view of the pipe in FIG. 6 with a section cut out ofthe pipe and a compartmental enclosure fit between the ends of the pipe;

FIG. 8 is a side view of the pipe and enclosure in FIG. 7 with anaeration device housed in the enclosure according to an exampleembodiment;

FIG. 9 is a side view of a tethered aeration apparatus of FIG. 1;

FIG. 10 is a side view of a submersible aeration apparatus with a remoteumbilical power and control unit according to an example embodiment;

FIG. 11 is a top view of the submersible aeration apparatus of FIG. 11;

FIG. 12 is a side view of a self contained aeration apparatus with acatamaran hull according to an example embodiment; and

FIG. 13 is a top view of the self contained aeration apparatus of FIG.12.

DETAILED DESCRIPTION

In describing embodiments of an apparatus and method for mixing gas andliquid, as illustrated in FIGS. 1-13, specific terminology is employedfor the sake of clarity. The disclosure, however, is not intended to belimited to the specific terminology so selected, and it is to beunderstood that each specific element includes all technical equivalentsthat operate in a similar manner to accomplish similar functions.

Referring now to FIGS. 1-13, there is illustrated a floating pressurizeddome aerator device and process for adding dissolved gas, such asoxygen, into liquid, such as fresh, salt and brackish water, wastewater,sewage and industrial waste. It is important to understand that theapparatus and method for mixing gas and liquid is suitable forutilization in any liquid environment where an increase in dissolved airor gas into liquid medium is desired or beneficial; therefore, while theapparatus and method for mixing gas and liquid is described convenientlywith the example utilization in a wastewater pond, it is not limited toapplication or implementation in such wastewater pond. Furthermore, theapparatus and method for mixing gas and liquid may be utilized in watersuch as but not limited to a golf course pond, water with aquaticplants, as well as water with fish and/or other marine life, fresh, saltor brackish water, wastewater, sewage or industrial waste. The apparatusand method for mixing gas and liquid is suitable for many applicationswhere air or other gas is to be dissolved into a liquid medium,including but not limited to golf course ponds, oxygen depleted lakes,streams, and rivers as well as environmental and/or industrialprocesses.

Referring now to FIG. 1, there is illustrated a fully enclosed floatingdome aerator device 10. Aerator device 10 is a mechanical gas dissolvingapparatus operating in a controlled pressurized environment. Dome 12 ispreferably supported by flotation device 14 proximate waterline 24 of apond or wastewater, sewage, industrial waste pond or other selectedliquid treatment reservoir including such as fresh, salt and brackishwater, wastewater, sewage and industrial waste. Dome 12 includes topportion 13 preferrably positioned above the surface of the pond, so asto define a space or compartmental enclosure 15 for containingmechanical aggitation of aerator device 10. Dome 12 is preferablyconstructed of an airtight and corrosion resistant material such asfiberglass or metal. It is recognized that other suitable materialscould be utilized without departing from the intended scope of thepresent invention. That is, dome 12 may be constructed of any materialcapable of holding the area defined by space or compartmental enclosure15 under the dome at a selected, preferrably increased barometricpressure.

Compartmental enclosure defined by dome 12 creates a space above thewaterline 22 that can collect foam and odor generated by aerator device10. Foam generated by aerator device 10 is thus held in close proximityto aerator device 10 and must travel back beneath waterline 24 toescape, further enhancing the transfer of gas to the liquid. Odorousgases generated by the mechanical agitation of aerator device 10 arealso trapped in dome 12 preventing their escape into the surroundingenvironment resulting in an essentially odor free operation. Inaddition, dome 12 acts as a sound barrier, trapping the noises generatedby the mechanical agitation of aerator device 10, preventing theirescape into the surrounding environment, and thereby resulting in anessentially noiseless operation.

Air source, such as blower 16, is preferably any common industrialvariable speed rotary type blower. Blower 16 can be of any standarddesign with air flow and pressure ratings capable of increasing thebarometric pressure of the air under dome 12 to preferably betweenapproximately 35-40 inches of mercury or 1-3 psi, however, greaterbarometric pressure can be utilized depending on the gas and liquidmedium being mixed. Blower 16 is preferably rotary, but can be any fan,centrifugal, rotary or any other type of blower or air source. Blower 16is preferably a single unit positioned proximate top portion 13;however, blower 16 can be in the form of a single or multiple blowersand can be located anywhere on aerator device 10 that permits air flowaccess to interior space 15 under dome 12. In the example operation,blower 16 increases the barometric pressure under dome 12 creating anideal environment for the transfer of gas to the liquid under dome 12,wherein coincidentally surface area is increased via agitation andwhirling of liquid by aerator device 10. In addition, the increase inbarometric pressure under dome 12 assists with popping the foam bubbles,effectively reducing the foam generated by aerator device 10.

Blower 16 can preferably be used for facilitating fine adjustment of theposition of the mechanical agitators of aerator device 10 relative tothe pond level 24. That is, because barometric pressure inside dome 12increases when blower 16 is in operation, this causes the liquid levelunder the dome 12 to be slightly lower than the static level of thepond.

Floatation device 14 is preferably a pontoon; however, flotation device14 can be made of any material and define any shape capable of keepingaerator device 10 afloat. Floatation device 14 is preferably attached toa submerged or floating frame 46 (not shown) for support and positioningof dome 12, lower housing 18, and other components of aerator device 10.Flotation device 14 preferably includes ballast 102 to allow foruser-controlled or controller controlled height adjustment of aeratordevice 10 in relation to waterline 24. Such ballast 102 allows theoperator or controller to adjust the position of aerator device 10relative to the static pond level, the specific gravity of the liquid,or the barometric pressure under dome 12. Flotation device 14 preferablyincludes maintenance deck 26 on top side 17 of flotation device 14,wherein maintenance deck 26 preferably extends outwardly along thecircumference of dome 12. It is recognized that flotation device 14 maybe detachable from frame 46 to reduce the width of aerator device 10 forease of transporting and flotation device 14 may be adjustable inrelation to frame 46 (up and down) and utilized to position aeratordevice 10 up and down relative to waterline 24 and flotation device 14.

Lower housing 18 preferably defines a partially submerged conduit havingclosed sides and bottom (not shown), thereby forming a submerged channelwith an open top (not shown) and opposing open sides 21 and 23. Lowerhousing 18 is preferably attached to frame system 46 (not shown). Lowerhousing 18 is preferably made of a watertight and corrosion resistantmaterial, however, lower housing 18 can be constructed of any materialcapable of directing the inflow and outflow of liquid through adesignated passageway. Open end 21, referenced as the intake 21,preferably has intake screen 20 to prevent debris, marine life, andlarge particulates from entering aerator device 10. In addition, openend 23 referenced as the discharge 23, preferably has discharge screen22 to prevent debris, marine life, and large particulates from enteringaerator device 10. Such screening enables positioning of intake 21 anddischarge 23 of lower housing 18 preferably submerged below the liquidline thereby creating a sealed environment and minimizing the noise,foam and odor escaping from aerator device 10.

Dome 12 is preferably affixed to lower housing 18, preferably via acorrosion resistant hinge 48 and latch 50 assembly (shown in FIG. 2).Although hinge 48 and latch 50 are preferred, any appropriate affixingmeans of any standard mechanism can be utilized, including but notlimited to nut and bolt, latch, lock, catch and/or clasp as long as theconfiguration is capable of holding dome 12 in contact with lowerhousing 18.

Drive 28 is preferably a variable speed AC or DC drive, including butnot limited to any gear reduction, belt, chain, or shaft driven. Drive28 can be any standard design with horse power, variable rotationalspeed, and directional ratings capable of rotating the mechanicalagitation of aerator device 10. Drive 28 is preferably fixed to frame 46of flotation device 14. Struts or brace members (not shown) preferablyprovide a generally rigid support for frame 46 and functions as amounting plate for drive 28. Power sources capable of operating drive 28and/or aerator device 10 include but are not limited to alternatingcurrent, direct current, compressed air, hydraulic and or solar power.

Controller 30 is preferably a multichannel digital motor control andsensor data receiver enabling recording of historical data andprogrammable control for automated operation of aerator device 10.Controller 30 can be any standard drive controller that matches drive28. Controller 30 may include other features such as a blower controllerthat monitors the pressure under dome 12 and regulates blower 16 tomaintain a specified pressure under dome 12. Controller 30 may alsoinclude a scheduler to preset hourly, night and day, daily, weekly,monthly seasonal and/or other runtime schedules for aerator device 10.Controller 30 may also include inputs from environmental sensors 31,including but not limited to wastewater temperature, dissolved oxygencontent of the wastewater or other liquid, pressure inside and outsidedome 12, dept of aerator device 10, water level inside compartmentalenclosure 15, and/or air temperature inside dome 12 wherein each sensorreading is preferably collected and available from inside, outside,and/or remotely from aerator device 10, in addition a light sensor todetermine and record whether the measurement is collected during nightor day. With these inputs, controller 30 is able to maximize theefficiency of the transfer rate of gas to liquid by modifying theoperation of aerator device 10 based on essentially real-time inputsfrom environmental sensors 31, wherein energy consumption is alsominimized. Controller 30 is preferably positioned proximate top portion13; however, controller 30 can be placed anywhere on aerator device 10that is accessible by an operator from maintenance deck 26 on top side17 of flotation device 14. Controller 30 can be remotely controlled by awireless radio frequency, infrared signal, or any other suitabletransmission and receive source, thereby enabling aerator device 10 tobe programmed or operated from a remote location.

As illustrated in FIG. 1, aerator device 10 preferably has lifting eye32 suitably fixed to frame 46 of flotation device 14. Lifting eye 32,together with frame 46 of flotation device 14, preferably enablesaerator device 10 to be lifted in and out of a wastewater pond via ahoist or crane. Lifting eye 32 can be in the form of a single ormultiple lifting eye(s) and can be located anywhere on aerator device 10suitable for attachment to frame 46 of flotation device 14.

Referring now to FIG. 2, there is illustrated a front cross-sectionalview of floating dome aerator device 10 with preferred placement of theinternal mechanics of aerator device 10 shown. Two drives 42 and 44 arepreferred and shown for aerator device 10, a leading drive 42 and atrailing drive 44. Leading drive 42 and trailing drive 44 preferablyrotationaly operate in the same direction and at the same speed;however, drives 42 and 44 are preferably capable of operating atdifferent speeds. For example, trailing drive 44 could operate at 2× thespeed of leading drive 42.

Both leading drive 42 and trailing drive 44 are preferably attached toframe 46. Frame system 46 is preferably made of a light weight andcorrosion resistant material, including but not limited to tubing,cables, and/or angled iron or aluminum, or combinations of the same orany other suitable material. Frame 46 can be constructed of any materialcapable of supporting and positioning leading drive 42, trailing drive44, dome 12, lower housing 18, flotation device 14, and the other systemcomponents of aerator device 10. Lifting eye 32 is securely affixed toframe system 46.

Vane 54 is a variable flow control device that can be mounted on intake21 or discharge 23 of lower housing 18. Vane 54 is preferably made of acorrosion resistant material. A plurality of vanes 54 preferably enablecontrol of the flow of liquid into and out of lower housing 18, therebymaximizing the transfer of gas to the liquid. The positioning ofplurality of vane 54 can preferably be set by an operator or controlledby controller 30.

Referring now to FIG. 4A, a front view of a preferred disc 60 is shown.Disc 60 is preferably a thin flat disc made of corrosion resistantmaterial. Disc 60 can be constructed of any material, configurationand/or dimension capable of being rotated through the sludge of liquid,such as fresh, salt and brackish water, wastewater, sewage andindustrial waste. Possible shapes and configurations include, withoutlimitation, a star, square, hexagon, octagon, and any otherconfigurations capable of defining a mixing area and a shear force zonewithin a liquid medium. Disc 60 preferably has keyed hub 62 at itscenter for affixing disc 60 to shaft 45 (shown in FIG. 4B). Althoughkeyed hub 62 is preferred, any suitable affixing means could be utilizedof any standard design with a means to attach disc 60 to a shaft 45. Thepreferred keyed hub 62 allows for disc spacing and adjustment on shaft45, thereby maintaining proper spacing.

Referring now to FIG. 3, a perspective view of preferred strake 70 isshown. Strake 70 is preferably made of a watertight and corrosionresistant material; however, strake 70 can be constructed of anymaterial capable of carrying liquid and/or gas. Strake 70 preferably hasquarter circle, unshaped or generally triangular shaped end cap 72, openleading face 74, trailing face 75 and mounting face 76, wherein faces74, 75, 76 preferably extend lengthwise along strake 70 formingperipheral edges of a channel for strake 70 to carry liquid and/or gas.Additionally, strake 70 preferably has a plurality of bleed holes 78defined through trailing face 75.

Strake 70 can be varied in size, shape, angle, and bleed hole placementto maximize aerator device 10 dissolved gas transfer rate in any liquidmedium. For example, a smaller strake moving at a higher speed may bemore effective on wastewater with high solids content, whereas a largestrake at lower speeds may be more effective on wastewater with smallersolids and also may be less disturbing to marine life. Furthermore,strake 70 can be varied in size, shape, angle, and bleed hole placementto account for the centrifugal force on the liquid. A plurality ofstrakes 70 are preferably secured to both sides of disc 60 in a radialconfiguration with each open face 74 oriented in same direction. Eachstrake 70 is arranged in a radial configuration beginning at the centerof disc 60 and extending outward to the outer circumference edge orperipheral edge of disc 60, wherein flat face 76 of strake 70 ispreferably affixed to disc 60, preferably via corrosion resistant boltand nut (not shown). Although corrosion resistant bolt and nut arepreferred, the affixing means can of any standard mechanism, and may beselected dependent on the material used for disc 60 and strake 70,including but not limited to welding, adhesive, or epoxy. Theillustration shown in FIG. 3 is not a specification or limitation on thenumber of strakes 70 affixed to disc 60.

Referring now to FIG. 4A, a front sectional view of a pair of preferreddiscs 60 is shown, depicting the preferred arrangement, area of overlap,and direction of rotation. Leading disc 81 and trailing disc 92 arepreferably arranged so they overlap as discussed below. Both discassemblies are preferably partially submerged in a liquid medium,preferably at a depth of at least 40% of their diameter; however, bothdisc assemblies can be submerged in a liquid medium to any depth,wherein at least part of the disc assemblies are exposed to theatmosphere under dome 12. Mixing area 100 is created below liquid line24 between where the leading disc 81 and trailing disc 92 overlap asalso depicted in FIG. 5. The plurality of strakes 70 on leading disc 81capture liquid from the wastewater pond and carry it up into mixing area100. Plurality of strakes 70 on trailing disc 92 preferably capture airunderneath dome 12 and carry it down into mixing area 100.

As depicted in FIG. 4A, when strake 70 is rotated up out of the liquid,it carries liquid up and out of the wastewater pond. This carried liquidescapes through bleed holes 78, thereby creating additional liquidsurface area which comes into contact with air, thereby resulting in anadditional transfer of gas to the liquid. When strake 70 is rotated downinto the liquid, it carries air down into the wastewater pond. The airescapes through a plurality bleed holes 78, thereby creating additionalsubmerged air which comes into contact with liquid, resulting inadditional transfer of gas to the liquid.

Referring now to FIG. 4B, a top sectional view of two sets of pluralityof discs 60 intermeshed amongst each other are shown. Leading drive 42is connected to leading shaft 43 and one or more disc 60 (shown asleading disc assemblies 81, 83, 85, and 87) are preferably affixed toleading shaft 43. Trailing drive 44 is connected to trailing shaft 45and one or more disc 60 (shown as trailing disc assemblies 92, 94, 96,98, and 99) are preferably affixed to trailing shaft 45. Theillustration shown in FIG. 4B is not a specification or limitation onthe number of discs 60 in either array of discs or the number of shaftsor the number of drives. These variable parameters are determined by thedissolved gas requirements and other application requirements of theliquid being treated. The leading and trailing disc assemblies areplaced in parallel, with their properly spaced discs placed in anoverlapping, interlaced relation. Spacing between the discs 60 ispreferably accomplished using keyed hub 62; however, spacers (not shown)can be used. Preferably, the overlap between leading and trailing discassemblies is 45% of the diameter of disc 60; however, the amount ofoverlap between the two sets of discs may be adjusted by varying theparallel spacing of leading shaft 43 and trailing shaft 45 provided thedistance is less than the disc 70 radius.

Referring now to FIG. 5, an enlarged partial sectional view of aeratordevice 10 is shown, to facilitate explanation of the dynamics of mixingarea 100. Strakes 70 on leading disc 81 captures liquid from thewastewater pond and carries it up into the mixing area 100. Strakes 70on trailing disc 92 captures air from underneath dome 12 and carries itdown into mixing area 100, in addition to pushing liquid down intomixing area 100. Discs 81 and 92 and their two strakes 70 moving inunison together create shear force F between the upward and downwardmoving liquid within the mixing area, resulting in shear force F thatdrives air into the oxygen depleted wastewater. Shearing force F occursin oxygen rich mixing area 100 resulting in an increased transfer ofoxygen into the liquid, such as fresh, salt and brackish water,wastewater, sewage and industrial waste.

Referring now to FIG. 5, an enlarged partial sectional view of aeratordevice 10 is shown, to facilitate further explanation of additionaldynamics of liquid gas mixing area 100. Strakes 70 on the leading disc81 captures liquid from the wastewater pond and carries it up intomixing area 100. Plurality of bleed holes 78 in trailing face 75 ofstrake 70 on leading disc 81 will leak liquid into mixing area 100 asfluid eddies. Strake 70 on the trailing disc 92 captures air fromunderneath dome 12 and carries it down into mixing area 100. Pluralityof bleed holes 78 in trailing face 75 of the strakes on trailing disc 90leak flurries of air bubbles into mixing area 100. The flurry of airbubbles and fluid eddies combine in mixing area 100, thereby creating anincreased transfer of oxygen into the liquid, such as fresh, salt andbrackish water, wastewater, sewage and industrial waste.

It is contemplated in an example embodiment that strakes 70 of aeratordevice 10 could be configured to provide a cutting or chopping actionfor operation in high solid and/or high fiber, such as hair, bio solids,and the like, prevailing in primary wastewater sludge ponds. Morespecifically, strakes 70 could be configured having an I-beam end viewwith discs 81 or 92 running perpendicular through the center (‘-I-’) ofthe I-beam. The edges of the I-beam configuration may comprise sectionshaving raised or sharpened edges to cut through the high solid and/orhigh fiber, such as hair, bio solids, and the like.

The disc assemblies can be set in motion rotating in unison, or, theindividual drive speeds can be utilized, thereby allowing foressentially infinite combinations of liquid and air, shearing forces,liquid eddies, and/or flurries of bubbles, thus allowing for optimumtransfer of gas, such as oxygen into the liquid, such as fresh, salt andbrackish water, wastewater, sewage or industrial waste.

It is contempalted in an example embodiment that aerator device 10 issuitable for utilization and adaptable without flotation device 14 foruse in a pipe, such as a discharge pipe. Furthermore, it is contempaltedin an example embodiment that aerator device 10 is adaptable withoutlower housing 18 for use in a pipe, such as a discharge pipe. Aeratordevice 10 is preferably mechanically affixed and positioned inside thepipe. Preferably, the flow rate of the liquid in the pipe is adjusted tomaintain the liquid level where both disc assemblies are preferablypartially submerged in a liquid medium, preferably at a depth of atleast 40% of their diameter; however, both disc assemblies can besubmerged in a liquid medium to any depth, wherein at least part of thedisc assemblies are exposed to the atmosphere under dome 12.

Referring now to FIG. 6, a standard industrial waste water or dischargepipe 50 is shown. Referring now to FIG. 7, wherein discharge pipe 50 isshown with section 50A removed from discharge pipe 50 and replaced withsealed enclosure 112. Preferably, enclosure 112 is inserted into thespace where section 50A was removed so as to define a space orcompartment 115 for containing mechanical agitation of aerator device100. Enclosure 112 preferably is welded to discharge pipe's 50 ends 152,which remained after cutting or removing section 50A from pipe 50. It iscontemplated that enclosure 112 is preferably constructed of an airtightand corrosion resistant material such as fiberglass, metal or the like.That is, enclosure 112 may be constructed of any material capable ofholding the area defined by space or compartmental enclosure 115 sealedat a selected, preferably increased barometric pressure. It isrecognized that other suitable materials could be utilized without anapparatus and method for mixing gas and liquid. Moreover, enclosure 112may be affixed to discharge pipe's 50 ends 152 utilizing epoxy, nuts andbolts compressing a seal or sealant or other means known to one ofordinary skill in the art. Enclosure 112 is further divided into uppersection 113 of compartment 115, which creates a space above waterline124 and lower section 114 of compartment 115, which creates a spacebelow waterline 124 that contains the liquid medium flowing throughdischarge pipe 50 and enclosure 112. Similar to FIG. 1, upper section113 of compartment 115 creates a space above waterline 124 that cancollect foam and odor generated by aerator device 100. Foam generated byaerator device 100 is thus held in close proximity to aerator device 100and must travel back beneath waterline 124 to escape upper section 113of compartment 115, further enhancing the transfer of gas to the liquid.Odorous gases generated by the mechanical agitation of aerator device100 are also trapped in upper section 113 of compartment 115 preventingtheir escape into the surrounding environment resulting in anessentially odor free operation. In addition, upper section 113 ofcompartment 115 acts as a sound barrier, trapping the noises generatedby the mechanical agitation of aerator device 100, preventing theirescape into the surrounding environment, and thereby resulting in anessentially noiseless operation.

Referring now to FIG. 8 is illustrated an example embodiment of a fullyenclosed in-line pipe aerator device 100. Aerator device 100 is amechanical gas dissolving apparatus operating in a controlledpressurized environment of a discharge pipe 50. In-line pipe aeratordevice 100 operates similar to aerator device 10 of FIGS. 1-5; however,in-line pipe aerator device 100 does not include dome 12, flotationdevice 14, and lower housing 18. As in FIGS. 1-5 in-line pipe aeratordevice 100 includes discs 160 each having strakes 70 as shown in FIGS.3-5 operating as described in FIGS. 1-5 above functioning to transfergas to liquid, especially for increasing the concentration of dissolvedoxygen in the liquid medium of pipe 50.

Blower 116 is preferably any common industrial variable speed rotarytype blower similar to blower 16 of FIG. 1. Blower 116 can be of anystandard design with air flow and pressure ratings capable of increasingthe barometric pressure of the air in compartment 115 to preferablybetween approximately 35-40 inches of mercury or 1-3 psi, however,greater barometric pressure can be utilized depending on the gas andliquid medium being mixed. Blower 116 is preferably a single unitpositioned proximate upper section 117 of enclosure 112; however, blower116 can be in the form of a single or multiple blowers and can belocated anywhere on in-line pipe aerator device 100 that permits airflow access to interior compartment 115 of enclosure 112. In addition,blower 116 may be remotely positioned relative to compartment 115 ofenclosure 112 and pressurized air from blower 116 may be piped or tubedfrom blower 116 to compartment 115 of enclosure 112. In an exampleoperation, blower 116 increases the barometric pressure in compartment115 of enclosure 112 creating an ideal environment for the transfer ofgas to the liquid in compartment 115 of enclosure 112, whereincoincidentally, surface area is increased via agitation and whirling ofliquid by aerator device 100. In addition, the increase in barometricpressure in compartment 115 of enclosure 112 assists with popping thefoam bubbles, effectively reducing the foam generated by aerator device100.

Blower 116 can preferably be used for facilitating fine adjustment ofwaterline 124 in compartment 115 of enclosure 112 by increasing ordecreasing the barometric pressure of the air in compartment 115, thusmaintaining the waterline 124 at a predetermined position relative todiscs 160. By increasing the air pressure in compartment 115 ofenclosure 112, blower 116 causes waterline 124 to lower forcing theliquid medium out of enclosure 112 and into pipe 50. In contrast, byreducing the air pressure in compartment 115 of enclosure 112 blower 116causes waterline 124 to rise allowing the liquid medium to enterenclosure 112 from pipe 50. Moreover, blower 116 with feedback fromsensor 119 allows for user-controlled or controller controlled heightadjustment of waterline 124 in compartment 115 of enclosure 112 inrelation to discs 160 optimizing dissolve gas in the liquid medium ofpipe 50.

Sensor 119 preferably represents one or more sensors, including but notlimited to sensors to detect water level, gas pressure, the amount ofdissolved gas in the liquid medium, and humidity inside compartment 115of enclosure 112 and to provide a representative signal of suchinformation for feed back to a controller, user, or directly to blower116. Various means of sensing and types of sensors to detect liquidlevel, gas pressure, the amount of dissolved gas in the liquid medium,and humidity are known to one of ordinary skill in the art and arecontemplated herein.

Referring now to FIG. 9, illustrates an example embodiment of a tetheredaeration apparatus 200 of FIG. 1. Anchor device 210 is permanentlyaffixed to river or tidal bed 224 and extends above waterline 222 toprovide stationary anchor support for tethered aeration apparatus 200.It is contemplated herein that anchor device 210 may be any devicecapable of securing tethered aeration apparatus 200 in a moving liquidmedium such as river flow, tidal movements and the like, including butnot limited to buoys. Swivel attachment 226 provides an anchor point forone end 227 of cable 228 to affix to anchor device 210 and the other end229 of cable 228 is affixed to eye 132 anchoring tethered aerationapparatus 200 relative to anchor device 210, thus pulling tetheredaeration apparatus 200 through liquid medium shown travelling in thedirection of arrows 251. As river current shift or tidal waters alterdirection tethered aeration apparatus 200 preferably shifts positionsdown stream from anchor device 210 continuing to scoop flowing liquidmedium into open end 21, referenced as the intake 21 shown in FIG. 1.

Tethered aeration apparatus 200 operates similar to aerator device 10 ofFIGS. 1-5. As in FIGS. 1-5 tethered aeration apparatus 200 includesdiscs 160 each having strakes 70 as shown in FIGS. 3-5 operating asdescribed in FIGS. 1-5 above functioning to transfer gas to liquid,especially for increasing the concentration of dissolve oxygen in theliquid medium.

It is contemplated herein that tethered aeration apparatus 200 may bemoved or tugged (tug boat) to different locations and re-anchoreddepending on river flow, tidal conditions and/or gas to liquid transferrequirements, especially to achieve dissolve oxygen levels in the liquidmedium of interest.

Regenerative or recumbent generator 240 is shown in this embodiment ofthe tethered aeration apparatus 200, but may be utilized in the in-linepipe aerator device 100, floating dome aerator device 10, mechanicalagitation of aerator device 100, tethered aeration apparatus 200,submersible aeration apparatus 300 as well. Recumbent generator 240comprises direct current (DC) motor generator drives 28. Preferably,liquid medium flows past leading disc 181 forcing leading disc 181 toturn in the direction of liquid medium shown travelling in the directionof arrows 251 (FIG. 9) or arrow 51 (FIG. 8). Likewise, liquid mediumflows past trailing disc 192 forcing trailing disc 192 to turn in thedirection of liquid medium shown travelling in the direction of arrows251 (FIG. 9) or arrow 51 (FIG. 8). Preferably recumbent generator 240generates power from one or both leading disc 181 and/or trailing disc192 rotations and utilizes the electric power generated by recumbentgenerator 240 to compensate for any lag occurring in either leading disc181 and/or trailing disc 192 by powering drive 28 with electric powergenerated by recumbent generator 240, thus enabling synchronized orun-synchronized rotation of discs 60.

Land based power may be supplied to tethered aeration apparatus 200along cable 228 or locally generated power may be generated by energydevice 250. Energy generation device 250 may include, but is not limitedto solar, wind, static electricity, photovoltaic, electric generatorand/or storage batteries.

Referring now to FIG. 10, there is illustrated an example embodiment ofa side view of submersible aeration apparatus 300 (with dashed linesillustrating multi-shaft intermeshed plurality of mixing discs 60 asshown in FIG. 4A) with remote umbilical power and control unit 355.Submersible aeration apparatus 300 functions and operates similar toaerator device 10 of FIGS. 1 and 2 having similar elements such as dome12, waterline 24, top portion 13, space or compartmental enclosure 15,frame 46, lower housing 18, opposing open sides 21 and 23, intake screen20, discharge screen 22, vane 54, leading disc 81, trailing disc 92,mixing area 100, controller 30, environmental sensors 31, ballast 102enabling a multi-shaft intermeshed plurality of mixing discs 60operating under a submerged pressurized dome 12. It should be recognizedthat ‘similar elements’ for submersible aeration apparatus 300 mayrequire additional strength, rigidity, durability and the like tooperate when submersible aeration apparatus 300 is positioned at varioussubmerged depths.

Preferably, submersible aeration apparatus 300 further comprises remotepower and controller unit 355 a combination power supply 355A andcontroller 30. Remote power supply 355A is preferably any aircompressor, whether positive displacement or dynamic, for compressingair (or other gases) capable of increasing the pressure of air byreducing its volume; thus, transporting the compressed air thruumbilical line 351 to submersible aeration apparatus 300. It iscontemplated herein power supply 355A includes, but is not limited to,alternating current, direct current, compressed air, hydraulic and/orsolar power capable of powering drive 28, reversible air motors 328,and/or submersible aeration apparatus 300. Umbilical line 351 ispreferably any length tubing and/or wiring capable of transporting powerand/or sensor/control data between remote power and control unit 355 andsubmersible aeration apparatus 300. It is recognized that having theability to place remote power and control unit 355 remotely fromsubmersible aeration apparatus 300 or aerator device 10 enables quiet,almost invisible, and self contained power and control at anenvironmentally safe distance from marine habitat.

Preferably, hub 352 receives compressed air from remote air source,power supply 355A via umbilical line 351 and regulates and distributescompressed air to enclosure 15, ballast 102, and reversible air motors328. Hub 352, one or more switchable valves, is controlled by controller30 (includes electronics area, onboard computer, monitors, processor,storage, communications, data acquisition and transmission) and directsthe necessary quantity of compressed air to reversible air motors 328via pipe or tubing 353 to maintain the rotational drive velocity anddirection of reversible air motors 328. Moreover, hub 352 selects therotational direction of reversible air motors 328 enabling reverserotation of reversible air motors 328. Alternatively, controller 30 mayselect the direction whether forward, reverse, and/or speed of eachreversible air motors 328 by utilizing a switchable valve local toreversible air motors 328. By adjusting the speed of one reversible airmotors 328 in relation to any other reversible air motors 328,controller 30 can be utilized to steer submersible aeration apparatus300. Moreover, reverse direction of reversible air motors 328 allows forself cleaning of bleed holes 78, intake screen 20, as well as flushingout any sediment collecting in lower housing 18. In addition, hub 352comprises one or more switchable valves, which directs an appropriatequantity of compressed air to enclosure 15 under dome 12; thusevacuating water from enclosure 15 similar to a divers bell.

Furthermore, hub 352 regulates and distributes compressed air toenclosure 15 via pipe or tubing 354 to evacuate the water from enclosure15 under dome 12. Hub 352 regulates the level of fluid line 24A (fluidline, liquid line, and water line refers to the fluid line inside dome12, which may be the same as the body of fluid surface line unlessapparatus is submerged) within enclosure 15 under dome 12, like a divingbell. Thus, maintaining optimal operation of multi-shaft intermeshedplurality of mixing discs 60 operating above and beneath fluid line 24Aunder a submerged pressurized dome 12 at any depth. Preferably, hub 352comprises one or more switchable valves, which directs an appropriatequantity of compressed air to regulate the level of fluid line 24Awithin enclosure 15.

Henry's law states that at a constant temperature, the amount of a givengas dissolved in a given type and volume of liquid is directlyproportional to the partial pressure of that gas in equilibrium withthat liquid. i.e., the amount of air dissolved in a fluid isproportional with the pressure. Expressed as a ratio: c=k_(h)*p_(g)where c is the solubility of dissolved gas, where k_(h) is theproportionality constant depending on the nature of the gas and thesolvent, and where p_(g) is the partial pressure of the gas. Therefore,with an increase in the partial pressure of the gas under dome 12 anincrease in the solubility of the dissolved gas (oxygen) into the fluid(water) occurs within submersible aeration apparatus 300. As submersibleaeration apparatus 300 descends the pressure under dome 12 increasesresulting in an increased efficiency in dissolving gas (oxygen) into thefluid (water). For example, operating aerator device 10 or tetheredaeration apparatus 200 on the surface of water line 24 may result in5-15 parts per million (ppm) of dissolved gas (oxygen) into the fluid(water). Utilizing Henry's law and submerging submersible aerationapparatus 300 to depths having 10, 15, 20 or more atmospheres ofpressure results in 30-50 parts per million (ppm) of dissolved gas(oxygen) into the fluid (water). Henry's law results in a directcorrelation between pressure and suspendability of dissolved gas(oxygen) into the fluid (water). Therefore, the higher the pressureunder dome 12 whether via submersing apparatus 300 to depth orincreasing the pressure via blower 16 for device 10, device 100, andapparatus 200 a resulting increase in the rate of dissolved gas (oxygen)into the fluid (water) occurs for such device 10, device 100, apparatus200, and apparatus 300.

Dissolved oxygen moves into and out of water by diffusion. The rate ofdiffusion depends on the difference in oxygen partial pressure betweenthe liquid and gas phases—the greater the difference, the greaterdriving force moving oxygen from one phase to the other. Standardaeration efficiency (SAE) is the standard oxygen transfer rate dividedby the power requirement in horsepower (hp). Units arepounds-O₂/hp-hour.

Moreover, submersible aeration apparatus 300 pulls water into opposingopen side 23 through intake screen 20, into leading disc 81, which pullsgas depleted fluid into mixing area 100, and trailing disc 92 pushes airinto mixing area 100, and thereafter trailing disc 92 pushes gas richfluid through discharge screen 22 and out opposing open side 21.Preferably, intake screen 20 and discharge screen 22 prevent debris andmarine life from entering submersible aeration apparatus 300.

While under additional pressure due to the depth of submersible aerationapparatus 300, strakes 70 on leading disc 81 captures liquid from thewastewater pond and carries it up into the mixing area 100. Strakes 70on trailing disc 92 captures air from underneath dome 12 and carries itdown into mixing area 100, in addition to pushing liquid down intomixing area 100. Discs 81 and 92 and their two strakes 70 moving inunison together create shear force F between the upward and downwardmoving liquid within the mixing area, resulting in shear force F thatdrives air into the oxygen depleted wastewater. Shearing force F occursin oxygen rich mixing area 100 under pressure resulting in an increasedtransfer of oxygen into the liquid via Henry's Law.

Preferably, adjustable vanes 54 on opposing open sides 21 and 23 vectorthe water intake and discharge to assist in stabilizing submersibleaeration apparatus 300 during operation. Furthermore, submersibleaeration apparatus 300 comprises setting legs 357 of any length disposedon the underside of submersible aeration apparatus 300 or affixed toballast 102. Preferably, legs 357 maintain submersible aerationapparatus 300 a determined distance above the bottom B of the body ofwater reducing sediment intake into screen 20, sediment erosion, marinelife disruption and the like. It is recognized that legs 357 may be ofany shape or configuration and include a foot or other broad surfacearea to prevent settling of submersible aeration apparatus 300 into thebottom B.

Referring now to FIG. 11, there is illustrated an example embodiment ofa top view of submersible aeration apparatus 300 illustratingmulti-shaft intermeshed plurality of mixing discs 60 as shown in FIG. 4Bwith dome 12 removed. Again, submersible aeration apparatus 300functions and operates similar to aerator device 10 of FIGS. 1 and 2having similar elements such as frame 46, opposing open sides 21 and 23,intake screen 20, discharge screen 22, leading disc 81, trailing disc92, ballast 102, leading shaft 43, trailing shaft 45, enabling amulti-shaft intermeshed plurality of mixing discs 60 operating under asubmerged pressurized dome 12 (not shown). It should be recognized that‘similar elements’ for submersible aeration apparatus 300 may requireadditional strength, rigidity, durability and the like to operate whensubmersible aeration apparatus 300 is positioned at various submergeddepths. Preferably, submersible aeration apparatus 300 further comprisesreversible air motors 328, umbilical line 351, hub 352, pipe or tubing353.

Leading drive 42 (shown as reversible air motors 328) is connected toleading shaft 43 and one or more disc 60 (shown as leading discassemblies 81 and the like) are preferably affixed to leading shaft 43.Trailing drive 44 (shown as reversible air motors 328) is connected totrailing shaft 45 and one or more disc 60 (shown as trailing discassemblies 92 and the like) are preferably affixed to trailing shaft 45.The leading and trailing disc assemblies are placed in parallel, withtheir properly spaced discs placed in an overlapping, interlacedrelation for dissolving gas into a fluid under waterline 24, andpreferably at depth under increased pressure.

Ballast 102 may preferably be used to retrieve or position submersibleaeration apparatus 300, or for height/depth adjustment and position ofsubmersible aeration apparatus 300 in relation to bottom B or waterline24 by increasing/decreasing the quantity of air in ballast 102. To raisesubmersible aeration apparatus 300, controller 355, hub 352, and pipe ortubing 356 preferably enable air from remote power supply 355A viaumbilical line 351 to enter ballast 102, thus, making submersibleaeration apparatus 300 buoyant. To lower submersible aeration apparatus300, controller 355, hub 352, and pipe or tubing 356 preferably enableair from ballast 102 to evacuate ballast 102, thus, making submersibleaeration apparatus 300 less buoyant. It is recognized that submersibleaeration apparatus 300 may be tethered as shown in FIG. 9.

Referring now to FIG. 12, there is illustrated an example embodiment ofa side view of self contained aeration apparatus 400 (with dashed linesillustrating multi-shaft intermeshed plurality of mixing discs 60 asshown in FIG. 4A) with a catamaran hull 452. Self contained aerationapparatus 400 functions and operates similar to aerator device 10 ofFIGS. 1 and 2 and submersible aeration apparatus 300 of FIGS. 10 and 11having similar elements such as dome 12, waterline 24, top portion 13,space or compartmental enclosure 15, frame 46, lower housing 18, blower16, opposing open sides 21 and 23, intake screen 20, leading disc 81,trailing disc 92, mixing area 100, controller 30, environmental sensors31, eye 32 (utilized for lifting, air lifting, towing, tethering and thelike), frame 46 enabling a multi-shaft intermeshed plurality of mixingdiscs 60 operating under pressurized dome 12.

Preferably, self contained aeration apparatus 400 further comprises hull452 a combination boat hull or flotation hull and fuel cell or fueltank. Hull 452 is preferably a catamaran style boat hull with flotationdevices 452 A&B configured on each side of multi-shaft intermeshedplurality of mixing discs 60. Hull 452 creates buoyancy for selfcontained aeration apparatus 400. It is recognized that hull 452 of selfcontained aeration apparatus 400 may be any flotation hull configurationcapable of floating multi-shaft intermeshed plurality of mixing discs 60and enabling liquid to enter and exit mixing area 100 within lowerhousing 18.

Furthermore, hull 452 is utilized as a storage tank or fuel tank 454 tostore fuel for operation of power plant 455 (whether mechanical,hydraulic, electrical, compressed air or the like) of self containedaeration apparatus 400, including power requirements for leading drive42, trailing drive 44 (drives may be mechanical, hydraulic, electricalcompressed air or the like), controller 30, blower 16, and environmentalsensors 31.

Preferably, self contained aeration apparatus 400 comprises steeringcontrol 456 and rudders 453. Steering control 456 and rudders 453 areutilized to direct discharged fluid from leading disc 81 and trailingdisc 92 exiting lower housing 18 at open side 21 to steer hull 452 ofself contained aeration apparatus 400. Rudders 453 extend belowwaterline 24 at open side 21 of hull 452 and function to steer hull 452of self contained aeration apparatus 400 when vectored discharge fromleading disc 81 and trailing disc 92 discharges across rudders 453 fordirectional control of self contained aeration apparatus 400. It isrecognized that leading disc 81 and trailing disc 92 may be used topropel hull 452 of self contained aeration apparatus 400 under thecontrol of steering control 456 and rudders 453 eliminating cable andpower tethers required for tethered aeration apparatus 200.Alternatively, self contained aeration apparatus 400 may be tethered ateye 32 proximate the front of hull 452 and operated as a stationary selfcontained aeration apparatus.

Referring now to FIG. 13, there is illustrated an example embodiment ofa top view of self contained aeration apparatus 400 illustratingmulti-shaft intermeshed plurality of mixing discs 60 as shown in FIG. 4Bwith dome 12 removed. Again, submersible aeration apparatus 300functions and operates similar to aerator device 10 of FIGS. 1 and 2having similar elements such as frame 46, eye 32, opposing open sides 21and 23, intake screen 20, leading disc 81, trailing disc 92, mixing area100, ballast 102, power plant 455, leading shaft 43, trailing shaft 45,drives 28, steering control 456, rudders 453, fuel tank 454, controller30 (includes electronics area, onboard computer, monitors, processor,storage, communications, data acquisition and transmission) enabling amulti-shaft intermeshed plurality of mixing discs 60 operating under apressurized dome 12 (not shown). Moreover, a cutter head may bepositioned proximate open side 23 to eradicate, remove, or harvest duckweed, algae or other aquatic plant growth. Still further, self containedaeration apparatus 400 may comprise operator station 458, control panel459, and seating 460 for manual operation and control of self containedaeration apparatus 400 or self contained aeration apparatus 400 mayoperate autonomously utilizing positioning system or pre-programmedcontrol.

Preferably, self contained aeration apparatus 400 further comprisestransmission 457, a gear system for transmitting mechanical power fromor drives 28 to leading shaft 43, trailing shaft 45. Furthermore,transmission 457 comprises shaft de-coupler 462 enabling decoupling oftransmission 457 from power plant 455. Alternatively, de-coupler 462 maycouple transmission 457 to recumbent generator 240 for gathering energywhen towing self contained aeration apparatus 400 through the water orby tethering self contained aeration apparatus 400 while tidal currentor river flow rotates leading disc 81 and the energy gathered fromleading disc 81 is transferred to trailing disc 92 via recumbentgenerator 240.

Furthermore, rotor baffles 463 positioned proximate opposing open sides21 and 23, more specifically extending between leading discs 81 on opensides 23 and between trailing disc 92 on open side 21 for reducing washor splash into self contained aeration apparatus 400 when in motion ortethered in heavy wave conditions.

Moreover, self contained aeration apparatus 400 further comprises hull452A and 452B a catamaran style boat hull with flotation devices 452Aand 452B configured on each side of multi-shaft intermeshed plurality ofmixing discs 60 to create a center tunnel starting with open side 23,intake screen 20, lower housing 18 (shown in FIG. 12), and open side 21.

It is recognized that self contained aeration apparatus 400 may compriseinstantiated units operating in combination like a floating dissolvedgas (oxygen) into the fluid (water) barge. Such barge may be towed orpropelled up and down a waterway, harbors, sounds and the like toeradicate large dissolved oxygen problems. In addition, this barge canbe stored in a regular barge docking facility or anchor.

It is further recognized that self contained aeration apparatus 400 maybe relatively small such as seven rotors, 40 horse power plant, andapproximately 10 feet in length enabling transport to bodies of waterthat are being stressed by algae blooms, sewage spills, and the like andcan benefit from quick restoration of dissolved gas (oxygen) into thefluid (water).

It is still further recognized that enclosed floating dome aeratordevice 10, mechanical agitation of aerator device 100, tethered aerationapparatus 200, submersible aeration apparatus 300, and self containedaeration apparatus 400 may comprise any number of leading discs 81,trailing disc 92, leading shaft 43, trailing shaft 45, rotor designsshown in FIG. 3 (whether for efficient transfer of dissolved gas(oxygen) into the fluid (water), to match the medium fluid (water), tooperate with chop suspended solids or chop fibrous material suspended influid (water)), instantiated units operating in combination and thelike.

Having thus described exemplary embodiments of the apparatus and methodfor mixing gas and liquid, it should be noted by those skilled in theart that the within disclosures are exemplary only, and that variousother alternatives, adaptations, and modifications may be made withinthe scope of the apparatus and method for mixing gas and liquid.Accordingly, the apparatus and method for mixing gas and liquid is notlimited to the specific embodiments illustrated herein, but is limitedonly by the following claims.

1. An apparatus for treating fluid by exposing the fluid to gas, theapparatus comprising: a) a dome, b) a lower housing supports said dome,said lower housing connected to said dome, wherein a sealed space isdefined under said dome and above a fluid line within said lowerhousing; c) an aeration means positioned within said sealed space andpartially submerged below said fluid line, wherein said aeration meanscomprises one or more parallel shafts, at least one first discpositioned axially on one of said shafts, at least one second discpositioned axially on another of said shafts, wherein said second discis interleaved relative to said first disc, and wherein a surface ofsaid first disc rotates in a direction opposite a surface of said seconddisc relative to each other resulting in a mixing area therebetween; andd) at least one air source, said air source enabling an effect therefromon the barometric pressure in said sealed space.
 2. The apparatus ofclaim 1, wherein said apparatus is submerged to depths having increasedpressure below a waterline.
 3. The apparatus of claim 2, wherein saidfirst and said second discs drive gas into the fluid at depth pressureincreasing the dissolved gas in the fluid.
 4. The apparatus of claim 2,further comprising a plurality of discs, said plurality of discs furthercomprising a leading disc and a trailing disc.
 5. The apparatus of claim2, further comprising at least one reversible air motor for rotatingsaid shafts and powered by a remote source of said air source.
 6. Theapparatus of claim 2, further comprising at least one strake carried bysaid first disc, each of said at least one strake defining a channelwith end caps, and at least one strake carried by said second disc. 7.The apparatus of claim 6, wherein said at least one strake is radiallydisposed.
 8. The apparatus of claim 6, further comprising a plurality ofbleed holes, said bleed holes defined in a trailing face of each saidstrake.
 9. The apparatus of claim 5, wherein said air source evacuatesfluid from said sealed space to the fluid line.
 10. The apparatus ofclaim 5, further comprising a controller, said controller adapted tocontrol said motor speed and the level of said fluid line.
 11. Theapparatus of claim 2, further comprising at least one sensor.
 12. Theapparatus of claim 11, wherein said sensor measurement is selected fromthe group consisting of dissolved oxygen, fluid line height, gaspressure, dissolved gas in the liquid medium, or humidity.
 13. Theapparatus of claim 2, wherein said first disc carries the gas into saidmixing area and said second disc carries fluid into said mixing areaproducing a shear force between the gas and the fluid increasing thedissolved gas in the fluid.
 14. The apparatus of claim 6, wherein saidstrake on said first disc carries gas down into said mixing area andsaid strake on said second disc carries fluid up into said mixing areaproducing a shear force between the gas and the fluid increasing thedissolved gas in the fluid.
 15. The apparatus of claim 5, wherein saidremote source of said air source and said controller are connected tosaid air motor and said dome by at least one umbilical line.
 16. Theapparatus of claim 2, wherein an increase in said depth of saidapparatus increases the barometric pressure in said sealed spaceenhances contact between said gas and said fluid within said sealedspace increasing the dissolved gas in the fluid.
 17. The apparatus ofclaim 5, further comprising a recombinant generator, said generatoradapted to assist said air motor.
 18. The apparatus of claim 1, furthercomprising a flotation hull for channeling fluid into said sealed spaceand for storage fuel therein.
 19. The apparatus of claim 18, furthercomprising a power plant for rotating said shafts.
 20. The apparatus ofclaim 19, further comprising at least one rudder for directional controlof a vectored discharge from said aeration means to steer saidapparatus.
 21. The apparatus of claim 20, further comprising an operatorstation for an operator to control said apparatus.
 22. The apparatus ofclaim 21, wherein said operator station operates autonomously of saidoperator.
 23. The apparatus of claim 19, further comprising arecombinant generator, said generator adapted to assist said powerplant.
 24. A method of mixing fluid, comprising the steps of: a)obtaining an apparatus comprising a dome, a lower housing supports saiddome, said lower housing connected to said dome, wherein a sealed spaceis defined under said dome and above a fluid line within said lowerhousing, an aeration means positioned within said sealed space andpartially submerged below said fluid line, wherein said aeration meanscomprises one or more parallel shafts, at least one first discpositioned axially on one of said shafts, at least one second discpositioned axially on another of said shafts, wherein said second discis interleaved relative to said first disc, and wherein a surface ofsaid first disc rotates in a direction opposite a surface of said seconddisc relative to each other resulting in a mixing area therebetween, andat least one air source, said air source enabling an effect therefrom onthe barometric pressure in said sealed space; b) trapping liquid betweensaid discs in a mixing area; c) forcing liquid up into said mixing areaby said first strake; and d) forcing liquid down into said mixing areaby said second strake.
 25. The method of claim 24, further comprisingthe step of submerging said apparatus to depths having increasedpressure below a waterline.
 26. The method of claim 24, furthercomprising the step of obtaining a flotation hull for channeling fluidinto said sealed space and for storage of fuel therein.